The present invention relates to a distillation column in which structured packing is utilized as a contacting element to bring liquid and gaseous phases of a mixture of atmospheric gases to be separated into intimate contact. More particularly, the present invention relates to such a distillation column in which the crimp angle of the structured packing is varied to optimize column height and performance.
In fractional distillation of a mixture of atmospheric gases, components of the mixture are separated in a distillation column. In the column, a vapor phase of the mixture ascends with an ever increasing concentration of the more volatile components (for instance, nitrogen) while a liquid phase of the mixture descends with an ever increasing concentration of the less volatile components (for instance, oxygen). Various packings are used within the distillation column to bring the liquid and gaseous phases of the mixture into intimate contact in order to accomplish mass transfer between the phases.
Structured packing has been found to be an attractive contacting element in many distillation applications for such reasons as simplicity of construction, uniform performance and low pressure drop. It has long been known that the only bar to the use of structured packing in most common distillations are cost constraints. Therefore, it is important that the structured packing be used in the most efficient manner from the standpoint of using the least amount of structured packing required for the distillation column.
As will be discussed the present invention provides a column design for separating atmospheric gases in which the height of structured packing utilized within the column is at a minimum for the particular distillation involved.